/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.tomcat.jni;

/**
 * Library
 * 
 * @author Mladen Turk
 * @version $Id: Library.java 939351 2010-04-29 15:41:54Z kkolinko $
 */

public final class Library {

	/* Default library names */
	private static String[] NAMES = { "tcnative-1", "libtcnative-1" };
	/*
	 * A handle to the unique Library singleton instance.
	 */
	static private Library _instance = null;

	private Library() {
		boolean loaded = false;
		String err = "";
		for (int i = 0; i < NAMES.length; i++) {
			try {
				System.loadLibrary(NAMES[i]);
				loaded = true;
			} catch (Throwable e) {
				if (i > 0)
					err += ", ";
				err += e.getMessage();
			}
			if (loaded)
				break;
		}
		if (!loaded) {
			err += "(";
			err += System.getProperty("java.library.path");
			err += ")";
			throw new UnsatisfiedLinkError(err);
		}
	}

	private Library(String libraryName) {
		System.loadLibrary(libraryName);
	}

	/*
	 * create global TCN's APR pool This has to be the first call to TCN
	 * library.
	 */
	private static native boolean initialize();

	/*
	 * destroy global TCN's APR pool This has to be the last call to TCN
	 * library.
	 */
	public static native void terminate();

	/* Internal function for loading APR Features */
	private static native boolean has(int what);

	/* Internal function for loading APR Features */
	private static native int version(int what);

	/* Internal function for loading APR sizes */
	private static native int size(int what);

	/* TCN_MAJOR_VERSION */
	public static int TCN_MAJOR_VERSION = 0;
	/* TCN_MINOR_VERSION */
	public static int TCN_MINOR_VERSION = 0;
	/* TCN_PATCH_VERSION */
	public static int TCN_PATCH_VERSION = 0;
	/* TCN_IS_DEV_VERSION */
	public static int TCN_IS_DEV_VERSION = 0;
	/* APR_MAJOR_VERSION */
	public static int APR_MAJOR_VERSION = 0;
	/* APR_MINOR_VERSION */
	public static int APR_MINOR_VERSION = 0;
	/* APR_PATCH_VERSION */
	public static int APR_PATCH_VERSION = 0;
	/* APR_IS_DEV_VERSION */
	public static int APR_IS_DEV_VERSION = 0;

	/* TCN_VERSION_STRING */
	public static native String versionString();

	/* APR_VERSION_STRING */
	public static native String aprVersionString();

	/* APR Feature Macros */
	public static boolean APR_HAVE_IPV6 = false;
	public static boolean APR_HAS_SHARED_MEMORY = false;
	public static boolean APR_HAS_THREADS = false;
	public static boolean APR_HAS_SENDFILE = false;
	public static boolean APR_HAS_MMAP = false;
	public static boolean APR_HAS_FORK = false;
	public static boolean APR_HAS_RANDOM = false;
	public static boolean APR_HAS_OTHER_CHILD = false;
	public static boolean APR_HAS_DSO = false;
	public static boolean APR_HAS_SO_ACCEPTFILTER = false;
	public static boolean APR_HAS_UNICODE_FS = false;
	public static boolean APR_HAS_PROC_INVOKED = false;
	public static boolean APR_HAS_USER = false;
	public static boolean APR_HAS_LARGE_FILES = false;
	public static boolean APR_HAS_XTHREAD_FILES = false;
	public static boolean APR_HAS_OS_UUID = false;
	/* Are we big endian? */
	public static boolean APR_IS_BIGENDIAN = false;
	/*
	 * APR sets APR_FILES_AS_SOCKETS to 1 on systems where it is possible to
	 * poll on files/pipes.
	 */
	public static boolean APR_FILES_AS_SOCKETS = false;
	/*
	 * This macro indicates whether or not EBCDIC is the native character set.
	 */
	public static boolean APR_CHARSET_EBCDIC = false;
	/*
	 * Is the TCP_NODELAY socket option inherited from listening sockets?
	 */
	public static boolean APR_TCP_NODELAY_INHERITED = false;
	/*
	 * Is the O_NONBLOCK flag inherited from listening sockets?
	 */
	public static boolean APR_O_NONBLOCK_INHERITED = false;

	public static int APR_SIZEOF_VOIDP;
	public static int APR_PATH_MAX;
	public static int APRMAXHOSTLEN;
	public static int APR_MAX_IOVEC_SIZE;
	public static int APR_MAX_SECS_TO_LINGER;
	public static int APR_MMAP_THRESHOLD;
	public static int APR_MMAP_LIMIT;

	/* return global TCN's APR pool */
	public static native long globalPool();

	/**
	 * Setup any APR internal data structures. This MUST be the first function
	 * called for any APR library.
	 * 
	 * @param libraryName
	 *            the name of the library to load
	 */
	static public boolean initialize(String libraryName) throws Exception {
		if (_instance == null) {
			if (libraryName == null)
				_instance = new Library();
			else
				_instance = new Library(libraryName);
			TCN_MAJOR_VERSION = version(0x01);
			TCN_MINOR_VERSION = version(0x02);
			TCN_PATCH_VERSION = version(0x03);
			TCN_IS_DEV_VERSION = version(0x04);
			APR_MAJOR_VERSION = version(0x11);
			APR_MINOR_VERSION = version(0x12);
			APR_PATCH_VERSION = version(0x13);
			APR_IS_DEV_VERSION = version(0x14);

			APR_SIZEOF_VOIDP = size(1);
			APR_PATH_MAX = size(2);
			APRMAXHOSTLEN = size(3);
			APR_MAX_IOVEC_SIZE = size(4);
			APR_MAX_SECS_TO_LINGER = size(5);
			APR_MMAP_THRESHOLD = size(6);
			APR_MMAP_LIMIT = size(7);

			APR_HAVE_IPV6 = has(0);
			APR_HAS_SHARED_MEMORY = has(1);
			APR_HAS_THREADS = has(2);
			APR_HAS_SENDFILE = has(3);
			APR_HAS_MMAP = has(4);
			APR_HAS_FORK = has(5);
			APR_HAS_RANDOM = has(6);
			APR_HAS_OTHER_CHILD = has(7);
			APR_HAS_DSO = has(8);
			APR_HAS_SO_ACCEPTFILTER = has(9);
			APR_HAS_UNICODE_FS = has(10);
			APR_HAS_PROC_INVOKED = has(11);
			APR_HAS_USER = has(12);
			APR_HAS_LARGE_FILES = has(13);
			APR_HAS_XTHREAD_FILES = has(14);
			APR_HAS_OS_UUID = has(15);
			APR_IS_BIGENDIAN = has(16);
			APR_FILES_AS_SOCKETS = has(17);
			APR_CHARSET_EBCDIC = has(18);
			APR_TCP_NODELAY_INHERITED = has(19);
			APR_O_NONBLOCK_INHERITED = has(20);
			if (APR_MAJOR_VERSION < 1) {
				throw new UnsatisfiedLinkError("Unsupported APR Version ("
						+ aprVersionString() + ")");
			}
			if (!APR_HAS_THREADS) {
				throw new UnsatisfiedLinkError("Missing APR_HAS_THREADS");
			}
		}
		return initialize();
	}
}
